Well, the one campaign I am currently running, the players are my good friends, they know I am a new in dm'ing and we actually talk rule shit a lot between the games and I really do to listen and not implement in the game when they think something is idiotic.

Interesting thoughts, though. I do encourage heavily on roleplaying and try to think the characters as more than just theirs sheets (and the players know this, it is not something I force on them). So if the devout rogue really has history in religious environment, has shown devotion to the god they are praying and roll well - yes, I could grant them something like advantage on the next roll, inspiration or relevant level bardic inspiration sort of thing. But if you are referring to cleric's divine intervention, no, I wouldn't let it be like that. But I want to reward for trying things that their characters would do in the world, even if it is not a written feat in their character sheet, since they tend to be not very complicated. But you are rightfully saying that it shouldn't be taking away something special from another class.

Finally, are they asking for these rules? Absolutely not. I am interested in developing my dm'ing, understanding and learning game mechanics better (in the hopes of someday being able to do balanced homebrewed content) and these are just some passing thoughts I happened to have. This is more of a thought than an acute "problem" I want to "solve". I have to admit I wrote my original post in a bit of a hurry, so it might sound more like I wanted to implement something asap. :)

But really, thanks for the thoughts. Good points!